Fluid-operated tool



C. A. HULTQUIST.

FLUID,OPERATED TOOL.

APPLICATION` FILED MAR. 24. 1919.

Patented June 8, 1920.

, l* l L H l J5 gli" Y Umransfr FLUID-OPERATED TooL.

. Specification of Letters Patent.

Application led March 24, 1919. Serial No. 284,793.

To all whom t may concern:

Be it known that I, CHARLES A. Honr- QUis'r, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Enid-Operated Tool, of which the following is a specification.

This invention relates to tools of the character operatedv by a fluid such, forinstance, as compressed air and an object ofthe invention, in general, is to provide a tool of this character having maximum efficiency.

Another object of the invention is 'to so construct the tool that the hammer will deliver its blow when traveling at maximum sp eed. y

Another object is to-avoid' waste of the operating fluid byso constructing the tool thatthe compressed fluid employed in operating the valve, which controls the reciprocative movement of the hammer,'wi ll, after opening the valve, pass into the cylinder to operate the piston.

Another object is to so construct the tool that the valve will not be kept from properly' seating by scale or the 'like from the fluid supply pipe.

Another object is to make provision for the reduction of pressure in front of the hammer, as it delivers its blow, to substantially that of the atmosphere.

Other objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention.

Figure 1 is a side elevation of a fluid operated tool constructed in laccordance with the provisions of this invention.

vFig. 2 is an enlarged elevation, mainly in vertical mid section, of the tool shown in Fig. 1, portions of the handle and drill steel being broken away to contract the view.

Figs. 3, 4' and 5 are plan sections on lines indicated by :r3- m3, 4-4 and 005-5, respectively, Fig. 2. j y

- Fig. 6 is a vfragmentary sectional elevation of a modified form of the invention.

There is provided a cylinder comprising a ,portion 1 oflarger inside diameter and 'a portion' 2 of smaller inside diameter, the portion 1 forming a chamber for the hammer or head 3 of a piston 4 which works in the cylinder portion 2. `The cylinder is partly formed in a barrel 5 and partly in a tion 2 is a The barrel 5 at its forwardA endy is closed by crear ortica.

' Patented June 8, 1920.

a frontv head 7 which may be a separate member, if desired by the constructor. The head 7 is tubular and in the bore 8 thereof is accommodated the head 9 of the drill steel' 10, said head projecting into the barrel 5 in a reduced portion 411 adapted to receive the blow delivered by the hammer 3. The drill steel 10 passes through the bore -12 of a drill steel retainer 13. The head 9. is preferably separate fromthe body of the drill steel .sov as to form an anvil block or tappet.

Any suitable means may be employed for fastening the barrel 5, 'heads 6, 7 and drill steel retainer 13 together toholdvthem assembled and such means, for example, may

' be constructed by providing the head 6 and drill steel retainer 13 with laterally projecting ears 14 through which bolts 15 pass so as to clamp the barrel 5 and head 7 between the head 6 and retainer 13. The barrel 5, heads 6, 7 and retainer 13 all together constitute the body of the tool. The head 7 may be provided with an annular rshoulder 16 adapted to fit-the bore of the barrel 5, and the steel retainer 13 may also be provided with an annular shoulder 17 adapted to fit the bore8 of the head 7.

The body is provided with a duct, one branch 18 of said duct opening into the rear 'end of the cylinder portion 2 and the other branch 19 opening into said cylinder portion adjacent the cylinder portion 5. When the piston 4 is in the retracted position shown in Fig. 2 the outlet end of the duct branch 19 is adjacent a reduced portion 20 of the piston so that the operating fluid entering said duct from the supply line, not shown, will discharge into the cylinder portion 2 and thence behind the hammer-3. The cylinder portion 5 is provided with an exhaust port 421 located substantially midway ofthe length of the cylinder portion 5.

Substantially midway of the cylinder porport 22 opening into a valve chamber 23 which forms ay portion of the barrel' 5 and which containsV a sliding tubular valve 24. Adjacent the port 22 the tubular valve 24 is provided with a reduced portion Y25 of'lessdiameter than the bore portion 27 of the valve chamber so that the operating fluid entering the port 22 from the` cylinder portion 2 willV press upon an annular shoulder 26 of the valve, said shoulder chamber.

lfitting the valve chamber portion 27. Thel valve chamber portion 27 is of larger diameter than the other portions of the vvalve The valve is provided with another shouldered portion 28 which lits a valve chamber portion 29 of smaller diameter than the portion 27, and a reduced portion 30 of the valve fits a reduced portion 31 of the valve chamber. pening into the portion 29 of the valve chamber is a duct 32 which communicates with the duct branch 18 so as to admit the operating fluid to the portion 29 of the valve chamber. rlhe valve 24 is provided with a relatively small relief port 33 'opening from the periphery of thevalve to the bore 34 thereof.

The valve chamber portion 27 is provided with a duct 35 opening into a duct 36, one end of the vduct 36 communicating with the atmosphere at the periphery of the body of the tool and the inner end of the duct 36 communicating with the portion 31 of the valve chamber. The'reduced portion 30 of the valve is provided with an annular groove 37 which registers with the duct 36 when the valve 24 is at the outer end of its movement the valve 24 is at the inner end of'its movebarrel.

ment the groove 37 is out of communication with the duct 36 and thus thevalve functions to close the duct 36.

Communicating with the valve chamber in the form of the invention shown in Figs. 1 to 5, at the reduced portion 31 thereof, is a duct 38, said duct being adapted to communicate with the annular groove 37 of the valve, especially when said valve is in its outermost position. The duct 38 communicates with the cylinder portion 5 at a point adjacent or somewhat above the level of the inner end of the drill head 9.

Opening from the inner or forward end of the inner end of the head 9 of the drill Y steel so that'when the hammer 3 isA in contact with the head 9 the operating fluid can flow into the cylinder portion 5 in front of the hammer 3. In Fig. 2 when the hammer 3 is in contact with the drill head 9, the hammer closes the intake end of the duct 38 so that fluid pressure at the front of the hammer will not be reduced by leakage of air through the duct 38, which, however, is -otherwise'controlled by means hereinafter to be described.

The valve chamber 23 may be closed at its rear end by a plug 40 screw-threaded into the barrel 5 flush with the. outer end of said The head 6 may be provided with a suitable handle formed, in this instance, by

a bar 41 extending through an eye 42of the head `6. Y

Now referring particularly to the modithe parts analogous to those described above are indicated by the same reference characters used to designate the same parts in the form ofthe invention shown in Figs. 1 to 5, and all the features previously described are present in this form with the exception of the duct 38 which is omitted. 1n lieu of said duct the valve 24 is provided with a port 43 opening from the vbore 34 of the valve into the groove 37 so' that when the valve is in the position shown in Fig. 6 air can escape from the bore of the valve to the groove 37 and thence through the duct 36 to the atmosphere.

' with an operating fluid supply, the operation of the invention is as follows: 1t may be assumed at the start that the parts are in the positions shown in Fig. 2 of the drawings. The operating fluid flows Vfrom the supply pipe, not shown, into the duct branch 18, thence to the rear or constant pressure face 44 of the piston 4 and the operating fluid also flows through the duct branch 19 to the cylinder behind the forward or intermittent pressure face 45 of the piston. The

vpressure of the operating fluid drives the piston on its outer or striking stroke and as soon as the reduced portion 20 of the piston passes out of registration with the kduct branch 19 the piston 4 will cut off the supply c of operating fluid from the reary pressure face 45 of the piston. Y

The piston 4 will continue on its striking stroke and when the rear pressure face 44 of the piston has passed by the port 22 the operating fluid in the cylinder portion 2 will discharge through the port 22 into the valve chamber portion 27 and press upon the shoulder 26 so as to move the valve 24 on its forward or port-opening stroke. It is to be noted that the plug 40, which forms one end of the valve chamber, is provided with a recess 46 in which the valve 25 seats when stroke, as in Fig. 2.L The valve 24 thus has a certain amount of lap so that the opening by the valve of the port 22 will occur after the valve has attained maximum speed, thus allowinga maximum amount of operating fluid to quickly flowrinto valve bore 34 after the valve has started to unclose the port 22. lIhe port 22 is so 'positioned 'relatively to the face 44 of the piston, and the lap of the-valve is made of such amount that the operating fluid entering the valve and flowing therethrough into the duct 39 will begin to discharge fromV the duct 39 into the cylinder'portion 5 just at the moment, but not before, the hammer 3 strikes the 'drill head 9. Before the operating fluid however, thus dischargesinto the cylinder in front of thevhammer 3, the hammer has passedl the port 21 which permits the oper- 110l said valve is at the end of its port-closingV Y Yating .alla in am portion of the cyanea to the rear of the hammer 4to escape to the atmosphere.

As the hammer 3 continues to move toward the drill head 9, after passing the port 2l, said hammer tends to compress the fluid that is in front of it in the gradually diminishing space in front of the hammer between said hammer and the head 7. In prior tools ofv this description this fluid pressure isnot relieved after closing of the exhaust port and consequently it forms a cushion to soften or minimize the force of the blow of the hammer upon the drill head, and therefore the drill steel does not deliver as hard a blow on the material vbeing drilled Y as would result if the blow of the hammer 3 were not so cushioned. In the form of this invention shown in Figs. 1 to 5, however, the air being compressed in front ofthe hammer is forced from that portion of the cylinder in front of the hammer throughl the duct 38, thence into the valve chamber 23. and from said valve chamber through the duct 36 t0 the atmosphere, the valve 24 not having moved into position to close the duct 36 until the hammer 3 almost reaches'the drill head 9.V Thus practically all of the pressure in front of the hammer 3 is eliminated before the hammer strikes the drill head. As soon as the valve 24 has moved into portopeningposition, it is clear that the portion 30 of the valvefunctions to close the duct 36, so that thev operating fluid discharging from the duct 39 into the cylinder in front of the hammer 3 cannot escape by way of the duct 38 to the atmosphere.

As above noted the operatingfluid discharges from the duct 39 into the cylinder in front of the hammer substantially at the moment that said hammer strikes, the drill head 9, and consequently the pressure of the operating fluid against the front face 47 of the hammer, as said hammer is brought to a stop against the drill head, will retract the piston or move it on its idle'stroke away from therdrill head 9. This movement'ofV the piston is effected in spite of the fact that the compressed air has access to the face 44 of the piston since the area of the rear pressure face 44 is less than the area of the front pressure face 47 of the piston. As the piston returns, it shuts the port 22 so as to lto the valve chamber through the duct 32 will operate against the valve shoulder 28 so as to return the valve to the port-closing position shown in Fig. 2. `When said valve begins to enter the recess 46, it of -course cuts off the escape of operating fluid from that portion of the valve chamber between the shoulder 26 and plug 40 but, owing to the provision of the duct 33, any remaining pressure that would tend to prevent perfect seating of the valvein the recess 46 will be eliminated through the duct 33. Any

tendency to scale and other particles interfering with closing of the valve is overcome by reason of the sliding contact of the valve on the sides of the recess 46. It may here be noted that when the valve 24 moves ,for-

wardly and rearwardly it is not retarded in said movement by any tendency to increase or reduction of air pressure in that portion of the valve chamber between the shoulder 26 and shouldered portion 29 of the valve chamber, since the pressure will be kept ati shown fragmentarily in Fig. 6, it is clearV that the operation is the same as above described for the form of the invention shown in Figs. 1 to 5 excepting that, instead of the fluid pressure in front of the vhammer 3 being relieved through the duct 38, the compressed uid will flow from`V the cylinder portionfin front of the piston through the duct39 to the valve bore 34, thence through the port 43 to the valve chamber portion 31 and thence through the duct 36 to the atmosphere.

It is noted that the shoulder 28 forms a constant pressure Vface and is of less area than the intermittent pressure face formed by the shoulder 26, and that therefore the valve will be moved into port-closing position as soon as the piston closes over the port 22 and opens the port 21. The dierence in areas of the shoulder 28 and shoulder 26 is a factor in the determination of the time of admission of the operating fluid into the cylinder in front of the piston since said difference governs the speed of travel of the valve. under any given fluid pressure. Other factors which determine the time of admission of the operating fluid to the cylinder are the position of the port 22 with reference to the face 44 of the piston and vthe rear end Vof the valve, and the amount of lap of the valve.

VFrom the foregoing it is clear that lthe construction provided by thisv f invention Y eliminates back pressure onV the piston during the striking stroke of the piston; that p the fluid operating the valve to port-opening` position isnotwastedbut is employed subn sequently in the cylinder to retract the piston; and that the valve performs the double function of controlling the admission of operating fluid -to the cylinder in front of the piston and the exhaust of a portion of said operating fluid from in front of the pistonY during the latter part of the Working or striking stroke of the piston.

It is to be noted that the construction described above provides against any Waste of the operating fluid for, When the piston moves onb its back stroke to close the port 22,

the compressed fluid caught in the port 22 passes from said portjthrough the relief,

the bore of the valve and, the duct 39 being axially alined with thevalve bore, the fluid flowsdirectly from the valve bore into theV duct 39 and thenceto the cylinder. Y

Y being a recess at the rear end of the valve The invention is not limited in its broader aspects to the exact details of construction described above and shown in the drawings, and therefore it is understood that the invention includes such changes and modifications as lie Within the spirit and scope of the appended claims;v

I claim: Y

1. A fluid operated drill comprising a cylinder having an exhaust port, a piston in the cylinder adapted to open and ,close the exhaust port, there being a valve chamber provided With an inlet port communicating with` the cylinder, said inlet port being opened and closed by the piston, a tubular valve in the valve chamber provided with a shoulder to receive pressure from the fluid admitted*y through the inlet port, said inlet port being adjacent one end of the valve chamber, there being a duct axially alined at its intake end with the valve. bore'and connected with the front end of the cylinder and there being a duct to admit operating fluid to the cylinderl rearwardly of theA piston. n y

2. A fluid operated drill comprising a cyl` inder having an exhaust port, a piston in the cylinder adapted to open andv close the exhaust port, there being a valve chamber provided'near itsv rear end with an inlet port communicating With the cylinder, they inlet port being adapted to'be opened and closed Vby the piston. a tubular valve-in the valve chamber. provided Witha shoulderto receive Vpressure on its rear face from the fluid admitted through the inlet port, there chamber adapted to receivethe rearV end of the valve to close the rear end of said valve,

linder having an exhaust port, a piston in 'being a duct opening from the front end of there being a relief port opening from `the valve bore between4 the shoulder and the rear end of the valve, there being a ductopening fromV the front end of the valve chamber and communicating with the front end of the cylinder and there being a duct to admit f operating fluid tov the cylinder rearwardlyV of the piston. l

3. A fluid operated drillfcomprising 'a -cylthe cylinder .adaptedV to open and close the exhaust port, there being a valve chamber provided near its'rear end( with an inlet port communicating With the cylinder, the 7 inlet port'being adapted to be opened and 80 closed by the piston, a tubular valve in the valvechamber provided With a shoulder to receive pressure on its rear face from the fluid admitted through the inlet port, there the valve chamber and communicating With, the frontend of the cylinder, there being a duct to admit operating fluid to theV cyliny der rearwardly of the piston, the valve hav- .ing asecond shoulder'and there being a duct 90 -to admit loperating fluid tothe valvek chamsaid port being controlled by the piston, and

a tubular valve controlling the flow ofthe fluid from the rvalve chamber into the bore Y i of thevalve and forming a conduitv for the fluid admitted through the port, and there. being a duct to convey the fluid from the valve chamber tothe front portion'of the cylinder.` 7

v5. Arfluid operated drill'havingea cylinder forming a piston chamber and a valve cham-l ber andhaving a port'establishing com-VV munication betvveen'one end of Y,thepiston chamber and valve chamber Yand a duct 115 j establishingl communicationbetvveen the opposite end of the piston chamber and valve chamber, a piston in the piston chamber controlling the port, and a tubularA valve inthe valve chamber closing said portv when in '1.20

one position and functioning las a movable conduit to establish communication kbetvveen the port Vand `duct when moved to a reverse position@ w l Signed at Los Angeles, California, this 1'25 17th day ofMarch, 1919. y

I CHARLES A. HULTQUIST.

Witnesses: Y Y. v

' GEORGE H.HILEs,

L. BELLE WEAVER. 

